We have initiated the fluorescence spectroscopic studies of dysplasia in hamster animal models, in order to understand the dynamic changes in the fluorescence spectrum in increasing degress of dysplasia, and attempt define the spectral changes at the time point of malignant transformation. So far we have conducted studies on cheek pouch mucosa of 7 golden Syrian hamsters. Carcinoma chnages were induced by applying 7,12 dimethylbenz(a)anthracene thrice weekly. Spectra were collected from normal control sites and the dysplastic sites at various intervals of time. The preliminary results indicate that when excited with 400 nm light, red fluorescence peaking at 630 nm increase with time and and apparently with increasing degree of dysplasia. This fluorescence intensity can potentially be used as a marker for dysplastic changes in the cheek pouch mucosa. The molecular origin of this red fluorescence and its role dysplastic alteration is under investigation.